1. Field of the Invention
The invention relates to an internal combustion engine spark ignition system. More specifically, the invention relates to an ignition coil designed to be mounted to a spark plug without damaging the ignition coil or the spark plug.
2. Description of the Related Art
The internal combustion engine can be categorized in several ways. One such way to categorize the internal combustion engine is whether the design requires a spark to combust the fuel within cylinders of the internal combustion engine. Diesel engines do not require a spark to be generated within the cylinders thereof. Non-diesel consuming internal combustion engines do, however, require a spark to ignite the fuel within the cylinders thereof.
With regard to non-diesel internal combustion engines the design thereof include the utilization of pencil ignition coils to operate the spark plugs. Recent developments in internal combustion engines include coils, sometimes called pencil coils, that are designed to be mounted directly to the spark plug. In addition, the pencil ignition coil is designed to primarily extend through the spark plug bore of the internal combustion engine. In other words, the pencil ignition coil is a long, thin pencil ignition coil designed to utilize the wasted space of the spark plug bore of the internal combustion engine.
U.S. Pat. No. 6,501,365, issued to Elliott et al. on Dec. 31, 2002 discloses an ignition coil having a generally circular core. The generally circular core is fabricated from a plurality of flat metal elements that are stacked together to create the core. The flat metal elements vary in widths such that the widths of the flat metal elements become smaller in size progressively as the flat metal elements are positioned away from the center of the core.
In addition, the lateral edges of the flat metal elements are angled such that they proximate a portion of a periphery of a circle. The resulting core includes two flat surfaces at either end where the last of the flat metal elements extend. While this design of a core increases the amount of metal within the core for increased performance of the ignition coil, the organization of the flat metal elements increases the time in manufacturing and keeping inventory on the cores for the ignition coils. Given the huge quantity of flat metal elements required to better proximate a circular core, a large amount of care must be taken to ensure each of the flat metal elements are aligned in their proper position with respect to the other flat metal elements. In addition, the flat metal elements can only be positioned in one of two positions and the orientation of the lateral sides is critical. It would be difficult to manufacture the core with a process that can accurately identify the orientation and position of each of the flat metal elements.
An ignition coil assembly provides a current to a spark plug to combust fuel in a cylinder of an internal combustion engine. The ignition coil assembly includes a primary winding defining a central axis. A secondary winding is wrapped about the primary winding coaxial with the central axis. The ignition coil assembly also includes a central core extending through the primary winding coaxial with the central axis. The central core includes a plurality of core components each having a single exterior surface that is continuous. In addition, the single exterior surface extends through an arcuate path.